Very dry, slightly medicinal blonde ale. Explanations?

I recently brewed a simple blonde ale:

3.0kg pilsner malt (86%)
0.25kg 60L crystal (7%)
0.25kg wheat malt (7%)
10g pacific jade (14.6%AA) at 60 mins
10g pacific jade at 10 mins
15g NZ cascade dry hop
Wellington NZ tap water (which I've used happily many times)

Mashed (thin) at 65.5C (150F) for about 80 mins
Fermented with S-05 for 16 days at 10-15C, 50-60F

OG=1.043, FG=1.010, 27IBU

My first taste, after it's been in the bottle for 3 weeks has me a bit worried, and I'm looking for explanations. The symptoms:

• It's very dry
• It's quite cloudy and has a "yeasty" aroma and flavour
• It has a slightly medicinal taste. Some better palates than mine identified a similar taste in another beer of mine as a brett infection. The bottles aren't gushers (yet) but the bugs may just be biding their time.

Possible explanations that I can see are:

• The very low mash temp (I've never mashed this cool before)
• The relative youngness of the beer
• An infection of some sort
• The cool fermentation

I'd most appreciate some feedback, especially as I re-used the yeast from this batch for two further batches (everything looked and smelled okay when I bottled) and am hoping they're not infected.

Sorry for the somewhat long-winded post, and thanks for any reassurance/advice you have.

You don't mention the yeast strain. It could be an artifact of the yeast strain that will mellow out with age, but it seems more likely to me that you either 1) have an infection by wild yeast/bacteria that is giving a phenolic flavor, or 2) somehow got sanitizer in the wort. The follow-on batches will tell all, since you did yeast harvesting. It is definitely not cool mash, cool ferment, and beer youngness is really unlikely for a beer of this strength.

What do you sanitize with?

In answer to the questions, I used S-05 to ferment (it's hidden in there in the original post )

I sanitise with acidified bleach (15-20ml bleach and 15-20ml vinegar in 10L of water) as discussed by Charlie Talley (developer of Starsan) in this podcast. Apparently at these concentrations it should work fine as a sanitiser and be undetectable flavour-wise (which has been borne out by my past experience with it.) I suppose it is possible I got a bit sloppy and left a large quantity of it in the bottling bucket, though I'd like to think I'm a bit more careful than that

Anyhow, thanks for replying. As Dos Locos says, I'll know soon enough anyway and really I was just wanting to share my anxiety.

>Bleach and low mash temp (probably went down below 150).

OK to make up for speed-reading the first post, here's another stab at it: Safale 05 is definitely not the source of phenolics at <15C fermentation temp. Your sanitation procedures sound solid. I use acidified bleach sometimes without problems, though I don't completely trust it as a no-rinse sanitizer. Chlorine can make some powerfully flavored compounds with organics. Even with good sanitation practice, there's always some risk that native microbes float into the wort after cooling, but before sealing the fermenter. I've only had that happen once, and that was brewing outside in Orlando in the summer. I wouldn't guess that would be likely in Wellington in the spring. One last diagnostic: if the phenolic flavor increases over time, it is probably infection.

Thanks again for everyone's input.

The bottles of the next batch with the same yeast (an APA, or NZPA if you prefer, as it uses all NZ Nelson Sauvin hops) were carbed up today, so I popped one and gave it a try.

They've only been in-bottle for a week, so they aren't perfect yet, but they show none of the same off flavours as the blonde. So (cross my fingers) this bodes well.

Thanks again for letting me share my stressing

I was under the impression that Brett takes many weeks to months to show "Brett character" ... it seems dubious to me that someone could state "that's a Brett infection" in a three week-old beer....

I once had a barrel-aged stout that had been dosed with a mixed culture 6 months previous and the "horse blanket" smell hadn't even shown up yet... if it's an infection, it's almost got to be something else.